Moscow city health department officials confirmed 12 cases of laser-blindness at the Central Ophthalmological Clinic, and daily newspaper Kommersant said another 17 were registered at City Hospital 32 in the centre of the capital.

Attendees at the July 5 Aquamarine Open Air Festival in Kirzhach, 80 km (50 miles) northeast of Moscow, began seeking medical help days after the show, complaining of eye and vision problems, health officials told Reuters.

Dozens of partygoers at an outdoor rave near Moscow have been partially blinded after a laser light show burned their retinas, say Russian health officials.

Moscow city health department officials say that 12 cases of laser blindness were recorded at the Central Ophthalmological Clinic in the city. The daily newspaper Kommersant reports that another 17 victims have registered at another hospital in the centre of the capital.